Swivel joints, especially between a containing body and a lid, are known to be a difficult problem to solve, not only in terms of the manufacturing cost, but also in view of the practical necessities associated with the use of the container.
When the container is in common use, it is possible to make do with simple solutions, and in this case there is generally less preoccupation with the esthetic considerations: boxes, card files, filing cabinets, etc. The opposite situation, which is characterized by strong esthetic constraints, is also encountered: fancy leather goods, bibelots, jewelry, inlaid work, etc., but in that case the production costs become secondary.
Aside from these extreme cases, numerous articles exist in which esthetics and cost must be balanced, and it will be appreciated that this problem is very difficult to solve, since an optimal solution to contradictory requirements must be found.
By way of example, this type of article can be considered to include makeup cases and other accessories intended to be kept in a handbag. In effect, aside from the fact that esthetics are primary, their usage must be simple and their shapes must be modest and smooth, that it, they must not have any angular, pointed, or sharp-edged part or anything likely to snag or catch. Accordingly, and in particular, this hinge must be as unobtrusive as possible.
However, the manufacture of the article and the mounting of the hinge must also be quite simple, so that the cost price will be as low as possible.
Numerous solutions have been proposed, but they do not liberate the designer from strictly geometrical imperatives, which dictate that the pivot pin of the hinge must be straight and must be located as close as possible to one of the sides, or outer edge, of the article. As a result, this side or outer edge must itself be straight and stands in the way of any esthetic attempt to use curved shapes, unless one is willing to move the straight hinge to the other side of the curved contour of the article; but in that case the article becomes less practical, its shapes are assertive instead of being modest, and its overall esthetics are destroyed.
French Patent No. 2.338.671 is known, for example, which describes compact including a body provided with a cap, a lid provided with a pivot pin and an intermediate piece that comes to cover the body and hold the pivot pin. However, the body and the intermediate piece have discontinuous outer edges, with recesses (12 and 16), and contrarily nothing is provided to hide the swivel joint, in particular by shifting it.
French Patent No. 2.458.243 is also known, which is similar to the aforementioned patent and likewise provides that the article has discontinuous outer edges (in this case, a "notch" 6 of the box half 2). This document describes nothing further in terms of shifting the swievel joint.